Department of Mathematics
Royal Holloway University Of London

Technical Report: Key Establishment Protocols and Timed-Release Encryption

Author: Qiang Tang

Reference: RHUL-MA-2007-9


This thesis is divided into two distinct parts. The first part
of the thesis explores security issues in key establishment
protocols, including both key distribution protocols and key
agreement protocols, and in both the general and the
password-based setting. The second part of the thesis explores
security issues of Timed-Release encryption schemes, especially
those with a Pre-Open capability.

In the first part, we initially present a formal description of
key establishment protocols, and summarise the security
properties that may be required of such a protocol. Secondly,
we examine existing security models for key establishment
protocols. We show that none of these security models fully
capture the desired security properties. Thirdly, we examine
some existing protocols and demonstrate certain
vulnerabilities. Some of these vulnerabilities have not
previously been detected because of the lack of a formal
security analysis, while others have been missed because the
adopted security models fail to address such security
vulnerabilities. Fourthly, we describe a novel security model
for general key establishment protocols, and we further adapt
it for the password setting. Finally, we propose key
establishment protocols which are proved secure in our novel
security model.

Download the full report from this page.

Department of Mathematics, Royal Holloway, University of London, Egham, Surrey TW20 0EX
Tel/Fax: +44 (0)1784 443093/430766